Notes/src/public/app/widgets/history_navigation.js

import BasicWidget from "./basic_widget.js";
import utils from "../services/utils.js";
import contextMenu from "../services/context_menu.js";
import treeService from "../services/tree.js";

const TPL = `
<div class="history-navigation">
    <style>
    .history-navigation {
        margin: 0 15px 0 5px;
    }
    </style>

    <a title="Go to previous note." data-trigger-command="backInNoteHistory" class="icon-action bx bx-left-arrow-circle"></a>

    <a title="Go to next note." data-trigger-command="forwardInNoteHistory" class="icon-action bx bx-right-arrow-circle"></a>
</div>
`;

export default class HistoryNavigationWidget extends BasicWidget {
    doRender() {
        if (!utils.isElectron()) {
            this.$widget = $("<div>");
            return;
        }

        this.$widget = $(TPL);

        const contextMenuHandler = e => {
            e.preventDefault();

            if (this.webContents.history.length < 2) {
                return;
            }

            this.showContextMenu(e);
        };

        this.$backInHistory = this.$widget.find("[data-trigger-command='backInNoteHistory']");
        this.$backInHistory.on('contextmenu', contextMenuHandler);

        this.$forwardInHistory = this.$widget.find("[data-trigger-command='forwardInNoteHistory']");
        this.$forwardInHistory.on('contextmenu', contextMenuHandler);

        this.webContents = utils.dynamicRequire('@electron/remote').webContents;

        // without this the history is preserved across frontend reloads
        this.webContents.clearHistory();

        this.refresh();
    }

    async showContextMenu(e) {
        let items = [];

        const activeIndex = this.webContents.getActiveIndex();

        for (const idx in this.webContents.history) {
            const url = this.webContents.history[idx];
            const [_, notePathWithTab] = url.split('#');
            const [notePath, ntxId] = notePathWithTab.split('-');

            const title = await treeService.getNotePathTitle(notePath);

            items.push({
                title,
                idx,
                uiIcon: idx == activeIndex ? "bx bx-radio-circle-marked" : // compare with type coercion!
                    (idx < activeIndex ? "bx bx-left-arrow-alt" : "bx bx-right-arrow-alt")
            });
        }

        items.reverse();

        if (items.length > 20) {
            items = items.slice(0, 50);
        }

        contextMenu.show({
            x: e.pageX,
            y: e.pageY,
            items,
            selectMenuItemHandler: ({idx}) => this.webContents.goToIndex(idx)
        });
    }

    refresh() {
        if (!utils.isElectron()) {
            return;
        }

        // disabling this because in electron 9 there's weird performance problem which makes these webContents calls
        // block UI thread for > 1 second on specific notes (book notes displaying underlying render notes with scripts)

        // this.$backInHistory.toggleClass('disabled', !this.webContents.canGoBack());
        // this.$forwardInHistory.toggleClass('disabled', !this.webContents.canGoForward());
    }

    activeNoteChangedEvent() {
        this.refresh();
    }
}